[Mimedefang] Testing HELO

[Geoff Thornton]

>Most of what this gets is spam, as I expected.  But amazingly,
>some legit hosts HELO with an IP that is not their own.  Or
>not so amazingly maybe.

I would assume that what you see is a result of internally homed mail exchangers being translated to a public address space by a firewall or NAT device.  They announce themselves by their internal address, but they would access the Internet using their translated address.

BTW--I also filter for bogus HELO's, but I only reject when someone claims to be my IP address or FQDN.  Since I'm homed using a public address, I know they can't be using that address or name themselves :-)


--Geoff Thornton
NetWorks Group